Brain computer interfaces (BCIs), which can control technology without physical movement offer great potential benefit to people with significant movement impairments. Regrettably, most current BCIs are dedicated devices that interface primarily with BCI-specific software, providing only limited functionality. While a significant investment of time and money could duplicate some of the functionality of commercial assistive technology (AT) in BCI-specific devices, a better approach is to create BCIs with universal/plug-and-play outputs to interface with commercial AT. These BCIs could replace physical input devices for the operation of commercial AT, linking BCIs with the full benefit of commercial AT at a minimum of cost and effort. At the same time, a plug-and-play BCI approach retains the benefits of product testing and technical support inherent in commercial AT products. Further, while current BCIs provide only extremely low typing rates and inaccurate mouse movements, the design of commercial AT for operation by people who type slowly and make inaccurate mouse movements could make plug-and-play BCIs more functional than BCI-specific devices alone. The proposed work will evaluate the capabilities of BCIs based on electroencephalogram (EEG) to interface with and control commercially available AT devices through the following specific aims: 1) Develop functionality within the NIH-funded BCI2000 research platform to produce universal/plug-and- play outputs that can replace the standard types of physical input devices (switch, keyboard and mouse) used to operate commercial AT;2) Study the ability of these universal/plug-and-play BCIs to control commercial AT;and 3) Evaluate the effect on BCI performance produced by AT features designed to improve accuracy of interface operation by people with limited physical abilities. The creation and evaluation of new universal/plug-and-play BCI functionality and the provision of the new BCI functionality to the over 100 research labs that utilize the BCI2000 is expected to make any commercial AT device into a potentially BCI-operated application. This will enable BCI researchers to utilize commercially available AT instead of investing time and effort duplicating AT functionality and reveal to AT practitioners the usefulness of the current state of BCI technology for their clients with progressive or extremely severe disabilities. Ultimately, the proposed work will challenge the BCI community in regards to the clinical utility of their current BCIs and the new BCI functionality will streamline BCI provision for people with degenerative conditions who could transition from physical interfaces to control AT to BCI operation of the same AT devices. By bridging the gap between the developing BCI technology and the established field of AT, the proposed research should advance the development of clinically practical BCIs for those with the most severe physical impairments and for others who may benefit from interfaces operable without physical movement. The primary objectives of the proposed work are to create and evaluate universal/plug-and-play brain computer interfaces (BCIs) that can operate commercially available assistive technology (AT). This would be a simple and cost-effective strategy for people with disabilities and AT practitioners, since previously purchased AT devices (and the time and effort invested in them) could still be utilized, with the BCI replacing a previously used physical interface. Creating the new BCI functionality within the NIH-funded BCI2000 research platform, which is utilized by more than 100 research labs worldwide, will impact the entire field of BCI research.